xen: fix identation of device files

Automatically:
 s/\t/    /g
 s/ +$//

Manually: align constant definitions in block.h

Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
loader.ld: merge init_array and ctors into init_array

put all of .ctors, .init_array, .ctors.*, init_array.*
into the init_array section.
This fixes the build for mixed ctors / init_array tooling
and dependencies.

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>